Process of preparing dialkylbarbituric acid.



NTTED STATES PATENT Patented November 22, 190%.

MAX ENGELMANN, OF ELBERFELD, GERMANY, ASSIGNOR TO FARBEN- FABRIKEN OF ELBERFELD CO, OF NEWV YORIQN. Y., A CORPORATION OF NEW YORK.

PROCESS OF PREPARING DIALKYLBARBITURIC ACID.-

SPECIFICA'IIONforr-ning part of Letters Patent No. 775,809, dated November 22, 1904.

Application filed August 4, 1904:. Serial No. 219,505. (No specimens.)

NH-OO OO O Q NH CO (R meaning alkyl radicals,) which bodies possess valuable therapeutic, especially soporific, properties. The process for the preparation of these compounds consists in first desulfurizing the 2-thio-4-6-diimino-5-dialkylpyrimidins having the formula NH-O NH The reaction is at an end after a short time. I

The 2-oxy 4 6 diimino 5 diethylpyrimidin separates on cooling. It is filtered oif,washed For the saponifiwith cold Water, and dried.

cation thirty parts of the product thus obtained are heated with sixty parts of a thirty-percent. sulfuric acid for four hours on the waterbath. After cooling the resulting 2-4-6-trioxy 5 diethylpyrimidin (dietlrvlbarbituric acid) is filtered olf and recrystallized from boilingwater. The splitting oflt of sulfur and the saponification can also be carried out with. other saponifying or other oxidizing agents.

The process proceeds in an analogous manner for the production of other dialkyl barbituric acids.

Having now described my invention and in what manner the same is to be performed, What I claim as new, and desire to secure by Letters Patent, is-

l. The process for the production of dialkylbarbituric acids having the above-given general formula, which process consists in first desulfurizingthefZ-thio-t-6-diimino-5-dialkylpyrimidins and secondly splitting off the imino groups in at and 6 position from the resulting Q-oxyl-(i diimino 5 diallrylpyrimid ins thus produced by treatment with saponifying agents, substantially as hereinbefore described.

2. The process for the production ofdiethylbarbituric acid, which process consists in first desulfurizingthe 2-thio l-6-diimino-5-diethylpyrimidin by means of oxidizing agents and secondly splitting off the imino groups in 4t and 6 position from the resulting 2-0Xy4-6- diimino-5-diethylpyrimidin by treatment with saponifying agents, substantially as hereinbefore described.

3. The process for the production of diethylbarbituric acid, which process consists in first desulfurizing the 2-thio-4-6-dii1nino-5-diethylpyrimidin by means of nitric acid and secondly splitting off the imino groups in a and 6 position from the resulting Q-oxyl-(S-dh in1ino-5-diethylpyrimidin by treatment with hot sulfuric acid, substantially as hereinbefore described.

In testimony whereof I have signed my name in the presence of two subscribing witnesses.

MAX ENGELMANN.

Witnesses:

O'r'ro KONIG, J. A. RITTERSHAUS. 

